How do I implement a multicolumn ComboBox DataGridColumn in a WPF DataGrid?

I have a simple question that I assume does not have a simple solution. I need to have a multi-column ComboBox for some g开发者_如何学Pythonrid columns in my WPF DataGrid. Is there a known best-practice to accomplish this? From what I have gathered this will require subclassing the DataGridComboBoxColumn to support a custom ComboBox.

I have found some examples of this but not supporting EF entities (I'm using Code First EF).

Any advice is greatly appreciated. Thanks

NOTE: This is all done dynamically with C#. I'm not using XAML to define columns.

Update: What I mean by multicolumn is simply that when you drop the ComboBox down I need to show two values for "Display", even though behind the scenes of course I'm still just storing an ID.

See here:.

With the exception that I need to do this as a DataGridColumn that can be dynamically created and added to a grid, rather than just the simple combo shown in the image.

Update I finally managed to find an article on CodeProject where the author has developed a control with my -exact- requirements. It is located here. Now the only problem I am trying to solve is how to allow the control to work when using Entity Framework (specifically, code first). Getting closer!

I have found the solution for my particular scenario. I downloaded the custom multi-column ComboBox with the included DataGridComboBoxColumn subclass from the link in my last update above. Basically I just made this work with Entity Framework Code-First POCOs and it solved my problem. Here is what I had to do to make it work with POCOs.

Inside of the CustDataGridComboBoxColumn there are a few overrides. You just need to slightly modify the following two overrides. I’m using reflection to change set the property since I don’t know what it will be from the control.

The original implementation accomplished this by getting the correct Row from the DataRowView with SelectedValuePath.

protected override object PrepareCellForEdit(FrameworkElement editingElement, RoutedEventArgs editingEventArgs)
{
      DataGridCell cell = editingEventArgs.Source as DataGridCell;
      if (cell != null)
      {
        // Changed to support EF POCOs
        PropertyInfo info = editingElement.DataContext.GetType().GetProperty("YourPropertyName", BindingFlags.Public | BindingFlags.Instance);
        object obj = info.GetValue(editingElement.DataContext, null);
        comboBox.SelectedValue = obj;
      }
      return comboBox.SelectedItem;
}

protected override bool CommitCellEdit(FrameworkElement editingElement)
{
    // Dynamically set the item on our POCO (the DataContext).
    PropertyInfo info = editingElement.DataContext.GetType().GetProperty(“YourPropertyName”, BindingFlags.Public | BindingFlags.Instance);
    info.SetValue(editingElement.DataContext, comboBox.SelectedValue, null);
    return true;
}

Also, if you intend on creating this custom control completely in code dynamically instead of in XAML, you will have to add a setter to the Columns property because by default it is set to read-only.

//The property is default and Content property for CustComboBox
[DesignerSerializationVisibility(DesignerSerializationVisibility.Content)]
public ObservableCollection<DataGridTextColumn> Columns
{
    get
    {
       if (this.columns == null)
       {
           this.columns = new ObservableCollection<DataGridTextColumn>();
       }
       return this.columns;
    }
    set
    {
       this.columns = value;
    }
}

Thanks for the views and answers provided. Sorry I was unable to adequately word the question to make more sense initially.

Can you clarify what you mean by multiple?

Are you looking to have something like either of these below?

[Column] (Combo) (Combo) (Combo) [Column]

or

[Column] 
(Combo) 
(Combo) 
(Combo) 
[Column]

If so you will need to implement a cell template for the column using the DataGridTemplateColumn Type.

http://windowsclient.net/wpf/wpf35/wpf-35sp1-toolkit-datagrid-feature-walkthrough.aspx

You can set this up in XAML and then just provide a collection to the grid for binding that will render the columns as needed.

what will be "YourPropertyName" means in : PropertyInfo info = editingElement.DataContext.GetType().GetProperty("YourPropertyName", BindingFlags.Public | BindingFlags.Instance);